My go-to ball has been my 15lb GT-1 for a couple years, I bowl on medium to heavy oil conditions and this ball would go long and snap hard. It was at 4k wet sand and power gel polish. Recently I feel like it died on me, it just rolls smooth off the back end and sometimes never recovers. I tried draining the oil by leaving it outside in the sun and wiping of the oil as I rotated it every 30 min. What are the correct steps to get this ball back to how it was before? On another note, can most pro shops help with figuring out a bowlers stats? It seems like if i knew my own stats, I could get my equipment fine tuned for my style.

I attached a pic of my GT-1 to show pin placement

I would definitely avoid leaving the ball in the sun, it doesnt work the same as a rejuvinator in a proshop.

On that note, take your equipment to a pro shop and have them resurface the ball and clean it up. This should restore the reaction to the ball.

If you want to know your numbers, a pro shop should be able to take the angles and measurements off of one of your balls for you. If you want to know speed and revs, that requires a video camera and some math.

I would disagree with that statement.
The core heats and cools at different rates, because the heat energy is transferring into the ball at first, but for the heat to dissipate, it has to then radiate from the center outward.

The only common material that expands when cooling, and shrinks when heated on Earth is water. I think you will find that ball materials (including ball plug) will expand with heat, and contract with cold. You are right about those expansion and contraction rates being different across the different densities of ball material, hence the danger for cracking when a ball is exposed to extremes in temperature.

Lane Masters says it is the core expanding and contracting in a 3 part ball that causes the cracking. They now make 2 part balls no fillers. Just Core and cover stock.
900 Global says it is from the cover drying out and to rub lane oil on a ball that is just siting around because it drys out . I have had 10 drilled balls split just sitting in my shop (all my personal balls) all different brands. So nobody knows for sure. Me i think it is the new plastics being used because a lot of older balls do not break just sitting around. I have an Inferno siting in my shop and it has been in the oven several times and it has not split even though it has not seen the lanes for a year now.